public class GOFBBlockCipher extends java.lang.Object implements BlockCipher
Modifier and Type | Field and Description |
---|---|
private int |
blockSize |
(package private) static int |
C1 |
(package private) static int |
C2 |
private BlockCipher |
cipher |
(package private) boolean |
firstStep |
private byte[] |
IV |
(package private) int |
N3 |
(package private) int |
N4 |
private byte[] |
ofbOutV |
private byte[] |
ofbV |
Constructor and Description |
---|
GOFBBlockCipher(BlockCipher cipher)
Basic constructor.
|
Modifier and Type | Method and Description |
---|---|
private int |
bytesToint(byte[] in,
int inOff) |
java.lang.String |
getAlgorithmName()
return the algorithm name and mode.
|
int |
getBlockSize()
return the block size we are operating at (in bytes).
|
BlockCipher |
getUnderlyingCipher()
return the underlying block cipher that we are wrapping.
|
void |
init(boolean encrypting,
CipherParameters params)
Initialise the cipher and, possibly, the initialisation vector (IV).
|
private void |
intTobytes(int num,
byte[] out,
int outOff) |
int |
processBlock(byte[] in,
int inOff,
byte[] out,
int outOff)
Process one block of input from the array in and write it to
the out array.
|
void |
reset()
reset the feedback vector back to the IV and reset the underlying
cipher.
|
private byte[] IV
private byte[] ofbV
private byte[] ofbOutV
private final int blockSize
private final BlockCipher cipher
boolean firstStep
int N3
int N4
static final int C1
static final int C2
public GOFBBlockCipher(BlockCipher cipher)
cipher
- the block cipher to be used as the basis of the
counter mode (must have a 64 bit block size).public BlockCipher getUnderlyingCipher()
public void init(boolean encrypting, CipherParameters params) throws java.lang.IllegalArgumentException
init
in interface BlockCipher
encrypting
- if true the cipher is initialised for
encryption, if false for decryption.params
- the key and other data required by the cipher.java.lang.IllegalArgumentException
- if the params argument is
inappropriate.public java.lang.String getAlgorithmName()
getAlgorithmName
in interface BlockCipher
public int getBlockSize()
getBlockSize
in interface BlockCipher
public int processBlock(byte[] in, int inOff, byte[] out, int outOff) throws DataLengthException, java.lang.IllegalStateException
processBlock
in interface BlockCipher
in
- the array containing the input data.inOff
- offset into the in array the data starts at.out
- the array the output data will be copied into.outOff
- the offset into the out array the output will start at.DataLengthException
- if there isn't enough data in in, or
space in out.java.lang.IllegalStateException
- if the cipher isn't initialised.public void reset()
reset
in interface BlockCipher
private int bytesToint(byte[] in, int inOff)
private void intTobytes(int num, byte[] out, int outOff)